William g



AM. PHDTO-LITHD. C0. NDL (DSBORNES PROCESS.)

@uiten tetes @anni ffirz.

IMPROVEMENT IN GUT-OIT VALVE GEAR.

l SPECIFICATION. TO ALL WHOM IT MAY CONCERN:

Be it known that I, WILLIAM G. PIKE, of Philadelphia, Pennsylvania, have invented certain new and useful improvements in Variable Cut-offs for Steam Engines, and I do hereby declare that the following is a full, .clear, and exact description of the construction and operation of the same, reference being had to the' annexed drawings, forming part hereof, and to the letters of reference marked thereon, in which drawings,

Fig. 1 is a vertical section on the line :v y of iig. 2 of the plug and shell'of the valve.

Fig. 2 is a horizontal section of said plug and shell, and a top view'of the yokes for lsuspending the plug, of the several devices used for operating the valve and of the lever, lifter, and trip, and of` part of .the rod by which the trip and lifter are connected vwith the governor of the engine.

Fig. 3 is a front view of the devices represented in fig. 2, showing also the combined steam cylinder and dash pot for closing the valve and cushioning the blow of the piston.

Fig. 4 is a rear end elevation of the steam cylinder and dash pot, the stand by which these parts are supported, the lifter and the bearing rods, with their springs, spring-boxes, and adjusting screws.

Fig. 5 is a top view of the combined steam cylinder and dash pot, cross-head, piston, and rods by which the piston is connected with the lower end of the double arm on the valvespindle.

The improvements herein described relate to the cut-oil` for which I obtained Letters Patent November 21st, 1865.

The drawings herewith tiled correspond, in the main, with the drawings annexed to said Letters Patent: to the latter being superadded the improvements which form the subject of the present application. It will therefore be unnecessary to describe the drawings in detail, except so far as they relate to the improvements.

Similar letters indicate similar parts in the two sets of drawings referred to, and also the same parts as represented in the di`erent figures.

In the specification annexed to said Letters Patent, the following occurs, viz: I is a spiral spring, one

end of which is attached to the arm G, and the other end to the support K. *This spring closes the valve. L.

is a bumper provided with a spring M to receive the bump of the arm G at the closing of the valve." I now dispense with the spring I and `bumper L, and, in lieu thereof, I use the combined steam cylinder and dash pot, the construction and operation of which I shall now proceed to describe.

a, gs. 3 and 5, is a steam cylinder about live inches long, the bore varying from i'ive-eighths of an inch to one inch in diameter, according to the size of the cut-oil. b,'figs. 3, 4, and 5, is the dash pot, about iive-eighths of an inch deep, the bore varying from three to three and a half inches in diameter, according to the size of the cut-oil'. c, igs. 3 and 5, is the piston; one end of it passing through the dash pot b', as shown.: rllhe cylinder and dash pot are made of cast iron, being cast in one piece and bored out as desired, leaving space enough between the cylinder and dash pot to receive the cross-head and allow the piston-head of the dash pot to make its stroke, which will vary from two to two anda half inches, according to the size of the cut-off. d, in the same figs., is the piston-head. e is the cross-head to which one end of the rods f f is attached, the other end of these rods being attached to the lower end of the double arm G of the valve spindle. g is a pipe for conveying steam from the steam space in the valve shell-to the cylinder a', where it acts constantly on the piston c, tendingl always to hold the valve closed. The pipe g will vary in diameter from about one-fourth to threeeighths of an inch, according to the size of the cut-off. This pipe is provided with a valve or cock i, by which the steam can be shut o` when necessary. i

In lieu of the springs marked R R1, in the drawings annexed to said Letters Patent, I'now employ bearing i rods surrounded by spiral springs and enclosed in boxes, the construction and operation of which parts I will now proceed to describe.

z' i', gs. 3, and 4, represent the two bearing rods, which are about four inches long,'shaped as shown, their upper ends being surrounded by spiral springs c k', their lower ends fitting boxes ll', which are of cast iron, of about five-eighth inch bore, and enclose both rods and springs, as shown. m m are screws working through the ends of the boxes l l', against plates fn. n', which rest on the tops of springs k k. By these screws Iobtain a greater or less pressure, as desired, on the rods S S', and thus secure auniform action of the trip.

p, figs. 3 and 4, is a stand. It is made of cast iron, is bolted to the stand N on the valve shell. and it furnishes support for the boxes and other parts last mentioned.

g, gs. 2 and 3. is the lifter. It hangs like a hinge, loose, on the trip spindle P. It is held up in working position by a removable pin r', which passes through ears s s on the lifter, and rests on the projection t from the trip. Y I

v The object of the lifter is to prevent the undue and destructive speed off the engine, which usually occurs when fromanyaccident the governor is thrown out of action. By the stopping of the governor the lever u, iig. 2, through which the trip spindle is connected with the governor, is thrown up, thereby raising the lifter, which throws thetrip rods S S out of action and leaves the valve closed, thereby stopping the engine.

Whenever the engine is stopped the pin r is withdrawn, and the lifter is allowed to drop down out of action. When the engine is started again, the pin r is replaced and the lifter brought into action.

Instead of connecting the cross-head e with the double arm Gr by means of two rods ff', as shown and described, it may sometimes be desirable toallow the cross-head toproject above the upper line of the cylinder, and use but one rod to connect it with the arm G. l

Having thus described my improvements, I claim and desire to secure by Letters Patent- 1. The combination of the double arm G, cylinder a and dash pot b', in the manner and for the purpose substantially as shown and described.

2. The spring-boxes' l l', with their enclosed springs 1c c, adjusting screws m m', and bearing rodsz' i', in combination with the rods S S', in the manner and for the purpose substantially as shown and described.

3. The lifter g, arranged and operating substantially as shown and described.

I WM. Gr. PIKE. Witnesses.

J. E. SHAW, Gno. E. BUCKLEY. 

